1. Field of the Invention
The invention relates to the art of hair curling, and more particularly to an improved permanent wave, mandrel device which includes a sponge member positioned between the elastic cord and the hair curled on the mandrel so as to distribute more widely the pressure applied to the curl.
2. The Prior Art
To understand the art of permanently waving hair, it is necessary to understand the nature of hair. Hair is manufactured by the body and is mainly formed of protein with some water and natural oil present. A hair strand as it grows in its follicle comprises about 6 to 10 outer circular layers, called a cuticle which surrounds an inner portion, or cortex, formed by many fibers of protein bonded together like a hemp rope. Hair growing from the follicle, at about the rate of 1/2 inch per month, undergoes a major change called keratinization about 1/3 of the way up the follicle canal. This is a change from soft living protein to hard, resistant non-living protein as occurs in human nails, animal horns, hooves and feathers. Keratinization renders the hair water insoluble and very resistant to chemical action.
The large protein molecules of the hair strand are joined together by electrical and chemical forces. Two of these forces are important to permanent waving. The first, called the "primary bond", is very strong and its position in the hair was established when the hair was formed. The next group of bands holding the protein molecules together are called "secondary bands". These are very weak bands which can be opened by water and this is the basis for temporary waving as by wet setting the hair. When hair is wet, the secondary bands are neutralized and the hair is soft. If the hair is then dried in a selected shape using a roller, pin, or comb, it will retain this shape as long as the hair is relatively dry since the secondary bands will hold the shifted position. But when the hair is rewet, the stronger primary bands take over and the hair reverts to its natural shape.
The only way to achieve a so-called permanent wave (lasting 21/2-3 months) is to change the position of the primary bands by exercizing a force with greater strength. Thus all permanent waving whether done by machine or by hand, by hot or cold methods, must perform three actions:
1. Open the primary bond (usually accomplished by a strong chemical curling lotion). PA1 2. Shift the position of these opened bond ends, (usually accomplished by rolling the hair on a spindle or rod). PA1 3. Reform the primary bands in the new shifted position (usually accomplished by a reforming chemical called a neutralizer.
Customarily the hair is cut and shaped before applying the three steps above. The hair is then moistened with the chemical curling lotion, usually thioglycolie acid (thio) or a derivative. If necessary, heat from a hair dryer is applied. This is the start of action 1.
Groups of hair strands locks are then individually rolled on small diameter spindles called "perm rods". Two pieces of paper are used with each lock of hair, one above and one below. The paper beyond the ends of the hair strands are rolled over the rod and subsequently the hair between the papers are rolled with the papers about the rod. This is continued beyond the papers as far as one can roll up to the scalp with the hair exposed around the rod and papers. In today's fashion generally involving shorter hair lengths, it is essential to roll the hair completely to the scalp. This is especially essential when creating poodle and "afro" hair styles and all other styles except those involving curling only the ends of the hair. An elastic band is then inserted across the length of the "perm rod" clamping the hair tightly, creating tension on the hair and a pulling sensation. All of the selected locks of hair are rolled on "perm rods" in this way, the number, positions, size of the perm rod, and directions of rolling depending upon the style of permanent desired. The described rolling on rods shifts the position of the opened bands along the hair strands.
The neutralizer lotion is applied to the hair curls around the rods and this hardens the hair to set the curls around the rods.
To complete the permanent, the rods are removed. A setting lotion is often applied to the hair curls. Depending on the style of permanent wanted, it may be that some hair locks will need to be rolled on larger diameter mandrels, usually called curlers. The head is then placed under a drier to dry the hair. Finally the curlers are removed and the hair is brushed and combed into the desired style.
One of the disadvantages of the conventional method and apparatus for permanent hair waving described above, is that the chemical curling lotion in acting on the hair rolled about the perm rod gives off heat which expands and softens the hair strands at the same time the elastic band holding the curl presses the curl tightly against the rod in a narrow area corresponding to the area of the band. Thus the force of the heat and the force of the band pressure together cause a crease in the softened hair. When the neutralizer is applied, the hair is hardened and damage occurs in the creased portions. Hair which has not been previously treated with strong chemicals (sometimes called virgin or `downy` hair) retains its elasticity. However, when it is treated with strong chemicals so as to achieve a long-lasting permanent by presently known available commercial methods, the hair is damaged and breaks by the creasing and hardening of the hair. Bleaching and tinting causes the hair to lose much of its natural elasticity and causes it to be much more susceptible to damage from the use of commerical chemical waving methods. Therefore, the use of conventional `perm rods` to give a permanent causes damage and breakage of the hair, and if the person has bleached or tinted hair, it is likely to cause very serious damage, including a very large number of broken short hairs.